About This Item

Share This Item

The AAPG/Datapages Combined Publications Database

Journal of Petroleum Geology

Abstract

Journal of Petroleum Geology, vol.27 (4), October 2004, pp 389-402
Copyright copyrght.jpg (4253 bytes) 2004 by Scientific Press Ltd. All rights reserved.

THE GENERATION OF IMMATURE OILS IN THE LACUSTRINE JIYANG MEGA-DEPRESSION, BOHAI BAY BASIN, CHINA

Zhang Linye*, Zhang Shouchun+*, Chen Zhilin*, Zhang Chunrong* and Hong Zhihua*

*Geological Scientific Research Institute of Shengli Oil Field Ltd. Co., SINOPEC, Dongying, Shandong, China.

+ author for correspondence, email [email protected]


The lacustrine Jiyang mega-depression (Bohai Bay Basin, eastern China) produces important volumes of immature oils. These oils were generated at shallow burial depths by source rocks which have not entered the conventional oil window. Oil-source correlation studies have determined that the oils were mainly generated by source rock intervals in the Es4 and Es1 Members of the Paleogene Shahejie Formation, which were deposited in saline- to brackish-water and brackish-water lacustrine conditions, respectively. Minor quantities of oil came from Es3 Member source rocks deposited in freshwater conditions.

Samples of the Es4, Es3 and Es1 source rocks underwent artificial maturation at low temperatures (100-400oC). For the Es4 sample, the hydrocarbon generation characteristics of soluble organic matter and kerogen were investigated. The results of the experiments show that soluble organic matter made a greater contribution than kerogen to the immature oil (76% versus 24%). A comparison of the results of the thermal simulation experiments with the naturally-occurring maturation profile shows that various factors influenced the generation of the immature oils. Firstly, the Es4 and Es1 Members include intervals enriched in algal material. Secondly, most of the immature oil is derived from soluble organic matter. Finally, the saline depositional environment was favorable for the preservation of organic matter.

Pay-Per-View Purchase Options

The article is available through a document delivery service. Explain these Purchase Options.

Protected Document: $10
Internal PDF Document: $14
Open PDF Document: $24